Hakim al Umma Maulana Ashraf Ali Thanvi (Allah have mercy on him) use to update and publish the list of his khulafa (appointed representatives) almost every year. This was to facilitate the search for spiritual mentors by seekers. 
Many new names were included for those who accomplished the required criteria to be a Shaikh. 

Few names were deleted. They included the dead and those who did not follow up regularly to ensure that they continued to stay and progress on the path. Some exclusions were for those who became distracted and fell into the traps of nafs and Shaytan. These points were explicitly mentioned in the updated list. 

Ma’asir e Hakeemul Ummat ra, 

Therefore, mere certificate of ijazet or khilafet is not enough. Continuous steadfastness on Shariah and spiritual progress is required.